PX4 MAVLink-Python Programming: 6. Flight Modes (PX4 Multicopter)

Hello, this is Aiden from the Marketing Team.

Today, I would like to introduce PX4 MAVLink-Python Programming – Flight Modes (PX4 Multicopter). Please note that this content is the registered copyright of QUAD Drone Lab, and we kindly ask you to refrain from unauthorized distribution.

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Flight modes support autopilot features to make it easier to manually control the vehicle, automate common tasks such as takeoff and landing, execute autonomous missions, or delegate flight control to external systems.

This topic provides an overview of the flight modes available for multicopters and helicopters.

Flight modes are categorized as either manual or automatic. Manual modes provide various levels of autopilot assistance when flying manually using RC control sticks or a joystick, whereas automatic modes allow the autopilot to have full control.

Manual – Easy:

• Position — This is the easiest and safest manual mode for vehicles equipped with position-fixing/GPS. The roll and pitch sticks control ground acceleration in the forward-back and left-right directions (similar to a car’s accelerator pedal), the yaw stick controls horizontal rotation, and the throttle controls the climb and descent speed. When the sticks are released, the vehicle levels out, comes to a stop through braking, and locks into its current 3D position despite wind or other forces.
• Position Slow — This is a speed and yaw-rate limited version of Position mode. It is primarily used when flying near obstacles or for temporarily limiting speed in accordance with regulations.
• Altitude — This is the easiest and safest non-GPS manual mode. The primary difference from Position mode is that when the sticks are released, the vehicle levels out and maintains its altitude, but it lacks an active braking or horizontal position-holding function. (The vehicle will continue to move based on its current momentum and will drift with the wind.)
• Stabilized – When the sticks are released, the vehicle levels out and maintains its horizontal attitude (but does not maintain altitude or position). The vehicle continues to move with its current momentum, and both altitude and horizontal position may be affected by the wind. This mode is also used when “Manual Mode” is selected in the Ground Control Station.

Manual – Acrobatic

• Acro – This is a manual mode for acrobatic maneuvers such as rolls or loops. When the sticks are released, the vehicle stops rotating on the roll, pitch, and yaw axes, but other forms of stability are maintained.

Automatic Modes:

• Position — The vehicle stops and hovers at its current position and altitude, maintaining its coordinates against wind and other external forces.
• Return — The vehicle climbs to a safe altitude, flies a clear path to a safe location (Home or Rally point), and then lands. This process requires GPS (Global Position Estimation).
• Mission — The vehicle executes a predefined mission or flight plan uploaded to the flight controller. This requires GPS (Global Position Estimation).
• Takeoff — The vehicle takes off vertically and then transitions to Hold/Position mode.
• Land — The vehicle lands immediately at its current location.
• Orbit — The vehicle flies in a circular path, constantly yawing to face the center. Radius, direction, and speed can be modified via RC control.
• Follow Me — The vehicle follows a beacon that provides position setpoints. The follow position can optionally be adjusted using RC control.
• Offboard – The vehicle follows position, velocity, or attitude setpoints provided via MAVLink or ROS 2.

Pilots switch flight modes using switches on a remote control or through a Ground Control Station (GCS). Some flight modes are only valid under specific pre-flight and in-flight conditions (e.g., GPS lock, airspeed sensors, or detection of the vehicle’s attitude along its axes). PX4 will not allow a transition to a specific mode until the appropriate conditions are met.

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재생

That concludes our look at Flight Modes (PX4 Multicopter), the sixth step in PX4 MAVLink-Python programming. I will return in the next post with a detailed guide on MAV_CMD.

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